He said the hospital should have investigated whether the high white cell count was a sign of infection and criticised staff for not considering the possibility of inserting a nasogastric tube on the morning that the woman was transferred to ICU with breathing problems.
"Given the woman's known problems, it appears that inserting a nasogastric tube should have been considered at this time to treat the issues stemming from her ileus and respiratory distress, and I am concerned that this did not occur," Hill said.
Further concerns about the care she received while in ICU were also raised and found there had been a delay in escalating her care to the consultant anaesthetist.
He also found that invasive ventilation should have been implemented sooner when it was clear that the woman was experiencing severe respiratory failure.
In response to the findings that Nelson Marlborough District Health Board was in breach of the Code of Health and Disability Services Consumers' Rights, the DHB has provided a written apology to the dead woman's family.
It has also produced new clinical guidance on non-invasive positive pressure ventilation and provided the commissioner with a copy.